message_defintions: added RADIO_STATUS, SIM_STATE and HIL_SENSOR

the RADIO_STAUS is a copy from ardupilotmega

HIL_SENSOR is intended to replace HIL_STATE, giving missing
information

SIM_STATE is used to provide feedback to ground stations on true SIM
state

Pair-programmed-with: Lorenz Meier
re-generate for new msgs
fix gen_all.sh for uppercase Python
pymavlink: re-generate python modules
fixed typo in ardupilotmega.xml
mavutil: added check_condition() method
mavutil: added MAVLink broadcast support
mavextra: use rotmat method of tilt compass calculation
pymavlink: added code to support mode change by name
pymavlink: added motors_armed_wait() and motors_disarmed_wait()

useful for copter testing
pymavlink: fixed default airspeed ratio
pymavlink: added some more useful mavextra functions

invert airspeed -> voltage
pymavlink: added support for logging sent packets

useful for debugging, and matches what mission planner does
pymavlink: regenerate module
Merge branch 'master' of https://github.com/mavlink/mavlink
Regenerate headers after merge.